Like you get all of the nutrients and you feel full and stuff. But you don't have to use the bathroom after. Could this be a thing in, let's say 22nd century?
Maybe. Look up space food if you're interested. That stuff is designed to be nutritional with the bare minimum of bathroom use required ... because that's really hard in zero gravity in space. Perhaps in the future that could be improved to be 100% efficient in terms of absorbency into the body with zero waste.
I think probably it's doable to avoid solid waste. As I understand it, most of what's excreted from our bodies is "extras" to the food, things we can't digest or don't need. So we poop them out. I'm a bit worried about not urinating... we use this process to remove a lot of toxins from the body, and I'm not sure how we'd manage without it.
Thing is, poop is not all used food. About 30% of what comes out of your bum is the bacteria that helped you digest your food. The issue with deliberately removing that bacteria from the equation - even if you could create food that is 100% absorbable and bioavailable - is that the same gut bacteria that is part of your digestive process is also a functional part of your immune system. Your body is in a "cold war" with all sorts of things, like candida for example. With nothing to keep candida in check, you've got some trouble to deal with. So, it's not just about making food that leaves no waste; there are other things to take into consideration. ETA: I'm not saying it would be impossible, just that it's a bigger question than just food that leaves no waste. Also, @BayView is correct about urination. One of the key purposes of urination is to remove nitrogenous waste from the body, and this waste product is one that has to do with biological processes in the body that are systemic and not just related to the ingestion of food and drink.
Seems like an interesting idea, but not one most find in films or books... Bathrooms are kinda like the magic edit out of such media, unless it is a shower or bath or sink. Toilets don't really exist, since we just kinda assume that happens off the record, and doesn't develop the characters. Though Barbies dog is the most economical look at recycling food and waste, even though it would not be an efficient design without some serious mcguffining to make it work in a closed loop fashion of eating, crapping, and being able to feed the waste back into the dog at a later time to reduce the process to said loop. So while you may be able to sustain a person on nutrient fluids for a good long while, eventually they will build up some solid waste over time that will need to be removed. Our bodies are not 100% efficient when it comes to using anything, hence excretions. Also oddly enough, the immune system is tied to what we consume. So while you could eradicate all disease for the most part, getting a cold could kill a person at that point. Which would be kinda embarrassing for a society that can cure all manner of illness. So unless you can evolve people to be more like plants, where the nutrient to waste ratio is different, due to it being in the form of gas (oxygen) and fruits/flowers. You might want to consider instead having people surgically implanted with an incinerator of sorts, that will completely destroy the waste leaving nothing behind (not even ash). Essentially if you really want to push the envelope, you could cheat a bit and just opt for downloading people into machines, so you don't have to worry about anything, except keeping around a good can of WD-40. But to keep any being organic, waste will always need to be managed, unless your a Lava Golem, in which case you can consume pretty much anything without a second thought really. ETA: Also living on zero solid fuel, people will evolve over time to not have teeth, since they will be useless since liquid can't be chewed. So while mouthwash will get a big boost in sales, toothbrushes and dentists will be a thing of the past. Just something to consider in your endeavor to change them in such a way to make them more metabolically superior.
This would only apply if we were still evolving based on natural selection, which we haven't been for some time. We don't allow our "less suitable" to die off, and we control reproduction to the point that our "more suitable" don't tend to have more offspring. If we were living in a world where people would be more likely to survive if they had smaller/fewer/less-teethy teeth, evolution might come into play. But we aren't living in that world now, and I don't know that we'll be living in that world in the OP's future, either.
Perhaps, but when you change the way things are they will manifest over time. At least that is how we understand how evolution works overall. So nature works by keeping what is used, and discarding what isn't. So we will not be the same in a few million years, so technically why would we have teeth if we lived on a diet that doesn't need to be chewed? Unless science manages to just supersede nature, we will always evolve with and without things as time passes.
I guess while I'm at it. For my dystopian world. The food on here is what the "resistance" eats. And that's actually better than what the citizens eat where it's just drugs made to suppress hunger and make them feel "full".
No, your body produces waste, always. There is no way to take in chemical fuel, extract energy from it, and not still have lower energy molecules left. Nothing happens to the atoms that you eat, they’re just rearrange, so they have to go somewhere. This is not just true for organics but anything that uses chemical energy.
I don't know why but this made me think of a line in the movie Two for the Road where Audrey Hepburn keeps talking about hamburger pills. Which it looks like she subsided on for this movie -- she's so thin!
I agree. At some points in my life, pooping is the only time I've ever been able to be alone. Why would I want to give that up? Also, as others have said, poop isn't just left over food. Any dead cells you accumulate just by being alive also end up as solid waste. We can probably greatly reduce it, but I don't think eliminating it entirely is really in the cards at the moment.
Not even in the 22nd century? It doesn't exactly take place "in this moment" it takes place nearly 100 years from now.
Well, if in the next 100 years we manage to stop cell death, stop the body from producing and excreting toxins, create a system of nourishment that gives energy without introducing mass into the body, make it economically feasible, and then convince people that it's a better idea than following nature, then sure. Why not? It's not really my story.
